//
// "$Id: fl_overlay.cxx 8864 2011-07-19 04:49:30Z greg.ercolano $"
//
// Overlay support for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2010 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
//     http://www.fltk.org/str.php
//

// Extremely limited "overlay" support.  You can use this to drag out
// a rectangle in response to mouse events.  It is your responsibility
// to erase the overlay before drawing anything that might intersect
// it.

#include "x.H"
#include "fl_draw.H"
#ifdef __APPLE__
#include "fltk_config.h"
#endif

//#define USE_XOR

static int px,py,pw,ph;

#ifndef USE_XOR
#include <stdlib.h>
static uchar *bgN = 0L, *bgS = 0L, *bgE = 0L, *bgW = 0L;
static int bgx, bgy, bgw, bgh;
#endif

static void draw_current_rect()
{
#ifdef USE_XOR
# if defined(USE_X11)
	XSetFunction(fl_display, fl_gc, GXxor);
	XSetForeground(fl_display, fl_gc, 0xffffffff);
	XDrawRectangle(fl_display, fl_window, fl_gc, px, py, pw, ph);
	XSetFunction(fl_display, fl_gc, GXcopy);
# elif defined(WIN32)
	int old = SetROP2(fl_gc, R2_NOT);
	fl_rect(px, py, pw, ph);
	SetROP2(fl_gc, old);
# elif defined(__APPLE_QUARTZ__)
	// warning: Quartz does not support xor drawing
	// Use the Fl_Overlay_Window instead.
	fl_color(FL_WHITE);
	fl_rect(px, py, pw, ph);
# else
#  error unsupported platform
# endif
#else
	if (bgN) {
		free(bgN);
		bgN = 0L;
	}
	if (bgS) {
		free(bgS);
		bgS = 0L;
	}
	if (bgE) {
		free(bgE);
		bgE = 0L;
	}
	if (bgW) {
		free(bgW);
		bgW = 0L;
	}
	if (pw>0 && ph>0) {
		bgE = fl_read_image(0L, px+pw-1, py, 1, ph);
		bgW = fl_read_image(0L, px, py, 1, ph);
		bgS = fl_read_image(0L, px, py+ph-1, pw, 1);
		bgN = fl_read_image(0L, px, py, pw, 1);
		bgx = px;
		bgy = py;
		bgw = pw;
		bgh = ph;
	}
	fl_color(FL_WHITE);
	fl_line_style(FL_SOLID);
	fl_rect(px, py, pw, ph);
	fl_color(FL_BLACK);
	fl_line_style(FL_DOT);
	fl_rect(px, py, pw, ph);
	fl_line_style(FL_SOLID);
#endif
}

static void erase_current_rect()
{
#ifdef USE_XOR
# ifdef __APPLE_QUARTZ__
	fl_rect(px, py, pw, ph);
# else
	draw_current_rect();
# endif
#else
	if (bgN) fl_draw_image(bgN, bgx, bgy, bgw, 1);
	if (bgS) fl_draw_image(bgS, bgx, bgy+bgh-1, bgw, 1);
	if (bgW) fl_draw_image(bgW, bgx, bgy, 1, bgh);
	if (bgE) fl_draw_image(bgE, bgx+bgw-1, bgy, 1, bgh);
#endif
}

/**
  Erase a selection rectangle without drawing a new one
  */
void fl_overlay_clear()
{
	if (pw > 0) {
		erase_current_rect();
		pw = 0;
	}
}

/**
  Draws a selection rectangle, erasing a previous one by XOR'ing it first.
  */
void fl_overlay_rect(int x, int y, int w, int h)
{
	if (w < 0) {
		x += w;
		w = -w;
	} else if (!w) w = 1;
	if (h < 0) {
		y += h;
		h = -h;
	} else if (!h) h = 1;
	if (pw > 0) {
		if (x==px && y==py && w==pw && h==ph) return;
		erase_current_rect();
	}
	px = x;
	py = y;
	pw = w;
	ph = h;
	draw_current_rect();
}

//
// End of "$Id: fl_overlay.cxx 8864 2011-07-19 04:49:30Z greg.ercolano $".
//
